Preheat the oven to 375 degrees. In a large bowl whisk the eggs then add the mozzarella, milk, ham, arugula, red pepper flakes, salt, and pepper. Gently mix until ingredients are combined, then set aside.
Heat one tablespoon of olive oil in a large cast-iron skillet over medium heat. Add the garlic and spring onions. Sauté for two to three minutes, then remove the skillet from the heat.
Pour the egg mixture into the skillet and gently stir to evenly distribute the ingredients. Place in the oven and bake for 15 – 20 minutes. Broil for one to two minutes to achieve a golden brown top.
